The present invention relates to the development of a new and distinct mutant of periwinkle, Catharanthus roseus, called xe2x80x98Dhawalxe2x80x99 produced by chemical mutagen treatment of the seeds and selection in widely cultivated variety xe2x80x98Nirmalxe2x80x99 of Catharanthus roseus. The mutant thus selected was selfed for several generations to achieve the homozygous true to the type plants maintaining stability of the genotype from generation to generation. The finally selected mutant, homozygous, selfed plant can be propagated by seeds obtained from self-pollination and also by terminal stem cuttings. Seeds of the variety xe2x80x98Dhawalxe2x80x99 have been deposited Sep. 12, 2002 under the Accession Number NCIMB 41147 at the international depository authority NCIMB (National Collections of Industrial, Food and Marine Bacteria) located at 23 St. Machar Drive, Aberdeen, AB24 3RY, SCOTLAND. The plant of the present invention is stable for commercial cultivation, which maintains the stability of the improved characters.
The genus Catharanthus belongs to the botanical family Apocynaceae, subfamily, Plumeriodae, tribe Plumariae and subtribe Alstoniiae. The first known species, C roseus was included in the genus Vinca (V. rosea) by Linnaeus. It was also called as Lochnera roseus. Originally endemic to Madagascar, this species has become naturalised in tropical countries and is generally grown as an ornamental plant.
This plant has been found to be a good source of anti-cancer alkaloids, vincristine (VCR) and vinblastine (VLB) and an anti-hypertension alkaloid, ajmalicine. The estimated value of the annual world demand for these alkaloids, VLB, VCR and ajmalicine is about $12 m, 3.5 m and 10 m respectively. Three varieties of the species namely, var. roseus with pink or rose coloured flowers, var. albus, with white flowers and var. ocellatus with white flowers and purple centre are known in C. roseus. A superior cultivar named, xe2x80x98Nirmalxe2x80x99 with high level of field resistance to dieback disease has been developed and released earlier by CIMAP.
Seeds obtained through self-pollination can propagate the genotypes of periwinkle. Terminal stem cuttings can also be useful for the propagation purpose.
The range of characteristics that are found among plants of this species suggest that further improvement by known breeding methods to obtain plants of unusual and valuable character is possible. The plant xe2x80x98Dhawalxe2x80x99 of this invention involves such an improvement. The present invention relates to a new and distinct plant called xe2x80x98Dhawalxe2x80x99 periwinkle, Catharanthus roseus as an induced mutant of variety xe2x80x98Nirmalxe2x80x99. These plant combines the characters of improved alkaloid yield with tolerance to the die back disease. This plant offers growers improved and high alkaloid yielding variety having high degree of resistance to dieback disease.
The main object of the invention is to develop a new variety of periwinkle called xe2x80x98Dhawalxe2x80x99 through mutagenesis, such that the plant is stable and suitable for commercial cultivation and produces higher herbage yields alkaloids in higher quality than the known and existing varieties.
The present invention relates to the development of a new and distinct mutant xe2x80x98Dhawalxe2x80x99 of periwinkle, Catharanthus roseus, produced by mutagenesis and selection from the seeds of widely cultivated variety of Catharanthus roseus, Nirmal. The mutant thus isolated and selected was selfed for several generations to achieve homozygous true to type plants maintaining stability of the genotype from generation to generation. The plant of invention is stable for commercial cultivation, maintains the stability of the improved characters. The plant produces higher herbage and alkaloid compared to other existing varieties.
Accordingly, the invention provides a new and distinct high alkaloid and greater herbage yielding plant xe2x80x98Dhawalxe2x80x99. It is distinct from the known variety of Catharanthus roseus, and is developed through chemical mutagen treatment.
The novel plant xe2x80x98Dhawalxe2x80x99 has the following combination of characteristics:
(a) light green to grayish green (emerald green 758/1) pubescent leaves with distinctly undulating leaf margin,
(b) green stem, white flowers,
(c) leaf yield of 1352 to 2557 kg/ha,
(d) yielding 0.89 to 1.40%, alkaloids in leaves,
(e) yielding 1.60 to 2.22%, alkaloids in roots,
(f) resistant to die-back disease,
(g) randomly amplified polymorphic DNA (RAPD) profile for polymerised chain reaction (PCR) amplified DNA segment using 4 primers (OPT 06, 09, 16 and 17) distinct from the other existing varietie(s), and
(h) higher herbage, alkaloid yield as compared to other existing varietie(s).
Accordingly, the present invention provides a hitherto unknown and distinct high alkaloid producing Catharanthus roseus plant called xe2x80x98Dhawalxe2x80x99 having the following combination of characters:
(a) plant height of 65-75 cm,
(b) light green to grayish green (emerald green 758/1) pubescent leaves with distinctly undulating leaf margin,
(c) green stem,
(d) white flowers,
(e) field resistance to die back disease.
(f) high leaf yield of 1352 to 2557 kg/ha,
(g) 0.89 to 1.40% of total alkaloids in leaves,
(h) 1.60 to 2.22% of total alkaloids in roots
(i) randomly amplified polymorphic DNA (RAPD) profile for polymerised chain reaction (PCR) amplified DNA segment using 4 primers (OPT 06, 09, 16 and 17) distinct from the other existing varietie(s), and
(j) higher herbage, alkaloid yield as compared to any other existing varietie(s).
The plant of invention xe2x80x98Dhawalxe2x80x99 is thus distinct, different, novel and has tremendous commercial application due to improved alkaloid content.